Sheet supporting means for tin plate sheet feeders



Dec. 28, 1943. e. E. NELSON ETAL 2,333,050

SHEET SUPPORTING MEANS FOR TIN PLATE SHEET FEEDERS Filed Sept. 3-, 1941 s Sheets-Sheet 1 8 4 mm p e Wm v, ww w WW %W $m. W. m WWQMV @a Q fiwmw W m WW h L} 1 2 g w m. MWWM i m4 J NW NW mm mm mm W HFH 1943- G. E. NELSON ETAL 2,338,050

7 SHEET SUPPORTING MEANS FOR TIN PLATE SHEET FEEDERS Filed Sept. :5, 1941 5 Sheets-Sheet 2 DecQ 28, 1943. E L N TAL' 2,338,050

SHEET SUPPORTINQg' MEANS FOR TIN PLATE SHEET FEEDERS Filed Sept. 3, 1941 3 Sheets-Sheet 5 jwuc/wbow Gear 8 E Nelson Carr/E Magn us Patented Dec. 28, 1943 SHEET SUPPORTING MEANS FOR TIN PLATE SHEET FEEDERS George E. Nelson and Carl E. Magnus, Chicago,

111., assignors to Continental Can Company, Inc., New York, N. Y., a corporation of New York , Application September 3, 1944, Serial No. 409,402 (01. 271-14) 11 Claims.

The invention relates generally to tin plate sheet feeding mechanisms in which the sheets are fed one-by-one from the top of a sheet pack, maintained at a substantially constant elevation, usually by suction gripper devices, and it primarily seeks to provide novel means for supporting the sheets intermediately of the corners thereof while they are being fed so as to prevent dragging of the individual sheets over the under- 1 lying pack. I

Sheet feeding mechanisms for feeding tin plate sheets one-by-one from the top of a pack maintained at a substantially constant feeding level are well known and an example of this form of machine including pneumatic sheet gripping de-.

vices engageable with the sheets at the corners thereof and means for. maintaining the sheet pack at a constant level is illustrated in the application for U. ,8. Letters Patent Serial No. 334,657, filed by Paul E. Pearson on May 11, 1940. In machines of this character, when the individual sheets are lifted by engagement of suction grippers or other lifting devices at the corners only thereof and are then moved longitudinally and presented to feeding rolls or the like for being fed out of the machine, there is a tendency for the flexible sheets to sag downwardly intermediately of the corner engaging lifting devices with the result that they drag over the underlying sheet pack and have protective or decorative coatings of lacquer or lithographing scratched or marred by this abrasive contact. It is, therefore, an object of the present invention to provide novel means for engaging and supporting the individually lifted and fed sheets intermediately of the corners thereof while they are being fed, thereby to prevent downward sagging of the sheets and the objectionable abrasive contact thereof above referred to.

In its more detailed nature the invention resides in the provision of means for engaging the sheets at their corners, or at least at the advance corners thereof, for individually lifting them from the pack of sheets, and means disposed intermediately of the corners of said sheets for magnetically attracting and supporting intermediate portions thereof while they are being fed from the machine thereby to prevent abrasive contact of the sheets'with the underlying sheet pack.

Another object of the invention is to provide sheet feeding mechanism of the character stated including intermedlately disposed sheet supporting units each embodying a roller equipment engageable in non-abrasive rolling contact with a sheet being fed, and means so disposed with rela- 7 will morefully appear, the nature of the inven-- tion to said roller equipment as to magnetically attract but not contact with the individually fed sheets.

Another object of the invention is to provide a sheet feeding mechanism of the character stated including lntermediately disposed sheet supporting units each comprising a pair of rollers engageable in rolling contact with a'sheet being fed, means formagnetically attracting and supporting lifted sheets so arranged withrelation to the roller equipments as to attract but not contact with the lifted sheets, and a pneumatic gripper equipment disposed in close relation to said roller equipment and effective to lift individual sheets into contact therewith.

Another object of the. invention is to provide in a feeding mechanism of'the character stated a pneumatic gripping and feeding unit, a. link mem-- ber supporting said unit and disposed in a generally horizontal position, a swingably mounted arm supporting one end of said link, a roller and guide groove equipment'for supporting the other end of said link, and means for imparting swinging movement to said arm for advancing a sheet lifted by said unit.

With the above and other objects in view which tion will be more clearly understood by following the description, the appended claims, and the several views illustrated in the accompanying drawings. y

In the drawings: Figure 1 is a somewhat diagrammatic side elevation and part vertical longitudinal section of a' sheet feeding mechanism embodying the invention, the initial sheet lifting condition of the parts being shown in full lines and the sheet advancing position of the parts being shownin dotted lines. I

Figure 2 is a plan view illustrating the invention, the sheet lifting units being shown in horizontal section. Figure 3 is an enlarged inverted plan view lillustrating one of the intermediately disposed sheet supporting units,

Figure 4 is a fragmentary detail vertical cross 1 section illustrating the mounting of one of the grooved guide brackets and the adjacent end of the magnet supporting rod.

Figure 5 is an enlarged fragmentary vertical cross section taken on the line 5-5 on Figure 1.

Figure 6 is an enlarged fragmentary end elevation illustrating the mounting of one of the sheet lifting units effective to lift the trailing end of a sheet.

In the example of embodiment of the invention herein disclosed, 5 designates the pack of tin plate sheets which may be supported by and maintained at a substantially constant elevation by any suitable mechanism, and an example of such mechanism may be found in the application for U. S. Letters Patent filed by Paul E. Pearson and hereinbefore referred to. The individual tin plate sheets are designated 6 and these may be lifted by two pneumatic units generally designated I at the trailing corners of the sheets and may be lifted and advanced by similar units generally designated 8 and disposed over the advance corners of the sheets.

The units 1 and 8 include a hollow plunger 9 equipped at its. lower end with a suction gripper I which may be evacuated at the proper time through a suction tube These plungers are projected against the sheets by air pressure supplied through tubes I2 and are spring returned to effect a lifting of the sheets. The suction and pressure applied through the unit tubes is controlled by a rotary valve in the particular machine illustrated in the patent application hereinbefore referred to and the detailed construction of these units and the manner in which the plungers thereof are pressure projected and spring returned will be apparent by reference to said application disclosure. The separation of the uppermost sheet 6 from the underlying pack during each sheet lifting and feeding operation is facilitated by the provision of well known winding devices I3, and these also may be controlled by a valve equipment such as is illustrated in the patent application referred to above.

The sheet feeding mechanism includes a constantly rotated cam shaft |4 rotatably supported in any approved manner on the machine framing and equipped with a sheet advancing cam l5. This shaft also carries a drop roll actuating cam I5 for alternately lifting and lowering the drop rolls I! which are disposed above and oppose continuously rotated feed rolls l8. The drop rolls are carried on supporting arms l9 mounted on a rock shaft 20 which also has a crank arm 2| secured thereto and equipped with a roller disposed for engagement with the control cam I6. See Figure 1.,

All of the parts hereinbefore described are disclosed in the Pearson application Serial No.

' 334,657 hereinbefore referred to and are constructed and operate in the manner ,therein disclosed. It is to be understood, however, that the present invention is not limited to the use of these specific forms of sheet gripping, lifting and feeding devices since the sheet supporting devices and feeding devices hereinafter described will operate efllciently with other sheet gripping and lifting devices well known in the art.

According to the present invention there are provided at least two, but preferably four, intermediately disposed gripper units generally designated 22 and which may be the same in construction and controlled in the same-manner hereinbefore described, but not necessarily so. When these gripper units are constructed as hereinbefore described, they include pressure projected, spring returned plungers 23 equipped with suction grippers 24 at their lower ends, the suction in each unit being controlled through a suction tube 25, and the pressure through a pressure tube 28.

The cylinder 21 of each of the units 22 is supported vertically in a bore 28 in a mounting head 29 having an extension horizontally bored at 30 to receive a mounting or supporting rod 3|, said extension being split as at 32 and securely clamped on said rod as at 33. If four of the intermediate units 22 are provided, two such rods 3| are necessary and these rods are disposed in parallel spaced relation to the axes thereof extending in the general direction in which the individual sheets 6 are fed. See Figures 2, 3 and 5. I

Each head 29 is equipped with two legs 34 which depend therefrom, one at each front and rear end thereof. The lower end of each leg is bifurcated and equipped with a roller 35 preferably formed of non-metallic, non-abrasive material. A permanent horse-shoe magnet 36 is removably secured by a. screw 31 "or the like to each of the legs 34 of each head 29, and it will be observed that the lower end extremities 38 of these legs are spaced slightly above the lower extremities of the rollers 35.

Each rod 3| is rigidly supported, as at 39, above the advance end of the sheets in a hanger bracket 40 which is vertically-adjustably secured, as at 4|, to a mounting bracket 42 clamp-secured, as at 43, on a cross rod 44 which is rigidly supported in any approved manner on the machine framing. See Figures 1, 2 and 4. At its other end disposed over the trailing end of the sheets each rod 3| is rigidly clamped, as at 45, in a hanger bracket 46 which is vertically-adjustably secured, as at 41, on a mounting bracket 48 clamp-secured, as at 49, on a cross rod 50 which is rigidly supported in any approved manner on the machine framing. See Figures 1, 2 and 6. The cross rod 50 may also serve as a support for the winding devices |3 hereinbefore referred to.

The rod 50 also has two mounting brackets 5| securely clamped thereon, as at 52, and extended ends of the brackets are clamp-secured, as at 53, to the corner gripper units 1 hereinbefore referred to, thus stationarily supporting said units. See Figures 1, 2 and 6.

The other corner gripper units 8 are clampsecured, as at 54, in vertical bores 55 provided in a pair of carrier links 55 which are disposed in a generally horizontal position. The links 58 are pivoted at their leading ends, as at 51, to crank arms 58 clamp-secured as at 59 to and depending from a rock shaft which is rockably supported in any approved manner on the machine frame. The shaft 60 has an actuator crank arm 3| secured thereon and equipped with a roller 62 for engaging the sheet advancing cam 15 hereinbefore referred to. The shaft 60 also has a crank arm '63 fixed thereon to which one end of an anchored spring 64 is connected, and

this spring serves to constantly hold the roller 32 in engagement with the cam l5. See Figures 1, 2 and 4.

The other or trailing'end of each link 56 is equipped with a laterally projected roller which rides in a supporting and guiding'groove 66 formed in the lower end of a bracket 61 depending from and clamp-secured, as at 68, on the cross rod 44 hereinbefore referred to. It will be observed that the supporting and guiding grooves 86 are disposed in a generally horizontal position but are inclined downwardly slightly in a direction toward the feed rolls l1, l8 hereinbefore referred to.

In the operation of the feeding mechanism the rotating cam l5 imparts a swinging movement to the crank arms 58 and a fore-and-aft movement to the links 56 which are supported in generally horizontal position by said arms and the inclined grooves 66.

Suction and pressure is suitably controlled and timed in the various lifting units I, 8 and 22 for causing the grippers l and 24 to be projected against and effect a lifting of the uppermost trailing end of a sheet, and in the intermediate grippers 24, is released prior to actual advancing of the sheet by forward swinging of the arms 58, and as these arms swing forwardly to present the advance end of the sheet between the feeding rolls ll, l8 in the well known manner, the sheet is drawn over the rollers 35.

' As previously stated, the intermediate suction grippers 24 and also the lower extremities 38 of the magnets are disposed slightly above the lower extremities of the rollers 35, and as each sheet is being moved forwardly it is supported intermediately of the corners thereof against dragging over the underlying pack 5. It will be understoodthat as each intermediate gripper 24 releases its grip on the sheet, the resiliency inherent in the rubber thereof will withdraw itfrom contact with the sheet, and thus each forwardly moved sheet engages only the rollers 35 while it is being moved forwardly and is held out of abrasive contact with the magnet ends 38, the intermediate grippers 24 and also the underlying sheet pack 5. In this manner abrasion of sheets during the advancing and feeding thereof is avoided and there is no danger of damaging decorative lithographing on the sheets or the protective coating of lacquer thereon.

It is of course to be understood that the details of structure and arrangement of parts may be variously changed and modified without departing from the spirit and scope of the invention.

We claim:

1. In a tin plate sheet feeding machine, means for lifting the sheets individually from a pack support, sheet feeding means, means for advancing the individually lifted sheets to said feeding means, and means disposed above a portion of each lifted sheet intermediately of the borders thereof for magnetically attracting and supporting the sheet out of contact with the underlying sheet pack while said sheet is being advanced to posed intermediately of the borders of and above the sheet toward the trailing end and the other similarly placed over the advance end of said sheet for attracting the lifted sheet, and a freely rotatable anti-friction element fixedly associated with each said magnet and disposed to contact the attracted sheet and hold it spaced from said magnet so as to be always out of abrasive contact with said magnet during advancement and feeding of'said sheet.

3. In a tin plate sheet feeding machine, a sheet drag preventing unit mountable and demountable as a unitary structure and disposed in spaced relation above a sheet pack and including a mounting unit, a sheet lifting means supported on said mounting unit projectible against and relower end and equipped with an anti-friction said feeding means, said last named means ineluding a stationary magnet for attracting the lifted sheet and a freely rotatable anti-friction element disposed in fixed relation to said magnet and effective to contact the attracted sheet and hold it spaced from the magnet so as to be always out of abrasive contact with said magnet during advancement of said sheet.

2. In a tin plate sheet feeding machine, means for lifting the sheets individually from a pack support, sheet feeding means, means for advancing the individually lifted sheets to said feeding means, and means disposed above a portion of each lifted sheet intermediately of the borders thereof for magnetically attracting and supporting the sheet out of contact with the underlying sheet pack while said sheet is being advanced to said feeding means and also while it is being fed away by said feeding means, said last named means including two stationary magnets onedistractable from the sheet pack for removing individual sheets therefrom for being individually fed in' the general direction of the plane of the sheet, a magnet fixedly supported on said mounting unit and disposed adjacentsaid means 'for attracting a lifted sheet and supporting the same while it is being fed, and a roller fixedly supported on said mounting unit and disposed adjacent said magnet for engaging in free rolling contact with the sheet as it is being fed and projecting slightly below the magnet for holding said sheet out of abrasive contact with the magnet as the sheet is being fed.

4. In a tin plate sheet feeding machine, a sheet drag preventing unit mountable and demountable as a unitary structure and disposed in spaced relation above a sheet pack and including a sheet lifting means engageable with sheets for placing them in position for being individually fed in the general direction of the plane of the sheet, a magnet fixedly supported on said mounting unit and disposed adjacent said means for attracting a lifted sheet and supporting the same while it is being fed, and an, anti-friction element fixedly supported on said mounting unit and disposed adjacent said magnet for engagingfree rolling contact with the sheet as it is being fed and pro- Jecting slightly below the magnet for holding said sheet out of abrasive contact with the magnet as the sheet is'being fed.

5. In a tin plate sheet feedingmachine, a sheet drag preventing unit mountable and demountable as a unitary structure and disposed in spaced relation above a sheet pack and including a mounting unit having a depending leg bifurcated at its roller, and a permanent horseshoe magnet secured to said leg and straddling said roller with the lower ends thereof disposed close to the roller and'terminating slightly above the lower limit of said roller whereby sheets attracted and supported by said magnet ends will engage in antifriction contact with said roller and be held thereby out of contact with said magnet ends.

6. In a tin plate sheet feeding machine, a sheet drag preventing unit disposed in spaced relation above a sheet pack and including a bracket having a depending leg bifurcated at its lower end and equipped with an anti-friction roller, a permanent horseshoe magnet secured to said leg and straddling said roller with the lower ends thereof disposed close to the roller and terminating slightly above the lower limit of said roller whereby sheets attracted and supported by said magnet ends will engage in anti-friction contact with said roller and be held thereby out of contact with said magnet ends, and a sheet lifting unit including a cylinder supported uprightly by said bracket and a plunger carried sheet gripper projectible against and retractable from the sheet pack for removing individual sheets therefrom for being fed in the general direction of the plane of the sheet, said gripper when in its inactive retracted position lying slightly above the lower extremity of said roller.

7. In a tin plate sheet feeding machine, a sheet drag preventing unit disposed in spaced relation above a sheet pack and including a bracket havinga leg depending from each of the front and rear ends thereof, each said leg supporting an anti-friction roller at its lower end, a permanent horseshoe magnet secured to each said leg and straddling the respective roller with the lower extremities thereof disposed slightly above the lower extremity of the respective roller, and a sheet lifting unit including a cylinder supported uprightly by said bracket intermediately of said magnets and a plunger carried gripper projectible against and retractable from the sheet pack for removing individual sheets therefrom for being fed in the general direction of the plane of the sheet, said gripper when in its inactive retracted position lying slightly above the lower extremity of said roller.

8. In a tin plate sheet feeding machine, sheet feeding means, a sheet lifting unit disposed over each of the four corners of the sheets of a pack from which the sheets are to be lifted and fed individually, means for imparting movement to certain of said corner units while a sheet is lifted thereby to advance said sheet to said feeding means, and a plurality of sheet drag preventing units each disposed in spaced relation above the pack and including a bracket having a leg depending from each of the front and rear ends thereof, each said leg supporting an anti-friction roller at its lower end, a permanent horseshoe magnet secured to each said leg and stradding the respective roller with the lower extremities thereof disposed slightly above the lower extremity of the respective roller, and a sheet lifting unit including a cylinder supported uprightly by said bracket intermediately of said magnets and a plunger carried gripper projectible against and retractable from the sheet pack for assisting in the removal of individual sheets therefrom for being fed in the general direction of the plane of the sheet, each said drag preventing unit gripper when in its inactive retracted position lying slightly above the lower extremity of said roller.

9. In a tin plate sheet feeding machine, sheet advancing means including a pneumatic sheet gripping and advancing unit, a link supporting said unit and disposed in generally horizontal position, a swingably mounted depending arm supporting one end of said link, a stationary bracket having a link supporting and movement guiding groove therein extending in the general direction of sheet advancingmovement, a roller carried by the other end of said link and sup ported and guided in said groove, and means for imparting swinging movement to said arm.

10. In a tin plate sheet feeding machine, means for lifting the sheets individually from a pack support, sheet feeding means, means for advancing the individually lifted sheets to said feeding means, and means disposed above a portion of each lifted sheet intermediately of the borders thereof for magnetically attracting and supporting the sheet out of contact with the underlying sheet pack while said heet is being advanced to said feeding means, said advancing means including at least one pneumatic sheet gripping and advancing unit, a link supporting said unit and disposed in generally horizontal position, a swingably mounted depending arm supporting one end of said link, a stationary bracket having a link supporting and movement guiding groove therein extending in the general direction of sheet advancing movement, a roller carried by the other end of said link and supported and guided in said groove, and means for imparting swinging movement to said arm.

11. In a tin plate sheet feeding machine, means for lifting the sheets individually from a pack support, sheet feeding means, means for advancing the individually lifted sheets to said feeding means, and means separate and apart from each of said lifting means and said advancing means and disposed above a portion of each lifted sheet intermediately of the borders thereof for magnetically attracting and supporting the sheet out of contact with the underlying sheet pack while said sheet is being advanced to said feeding means and including an anti-friction element engaged by the magnetically attracted sheet as it is being advanced.

GEORGE E. NELSON.

CARL E. MAGNUS. 

